首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   259384篇
  免费   18867篇
  国内免费   1145篇
耳鼻咽喉   2935篇
儿科学   6527篇
妇产科学   4617篇
基础医学   33092篇
口腔科学   10811篇
临床医学   25566篇
内科学   53950篇
皮肤病学   3455篇
神经病学   24390篇
特种医学   8433篇
外国民族医学   11篇
外科学   38987篇
综合类   3483篇
一般理论   318篇
预防医学   21548篇
眼科学   6567篇
药学   17008篇
  6篇
中国医学   361篇
肿瘤学   17331篇
  2023年   1675篇
  2022年   2425篇
  2021年   5471篇
  2020年   3366篇
  2019年   5330篇
  2018年   6172篇
  2017年   4783篇
  2016年   5311篇
  2015年   6264篇
  2014年   9054篇
  2013年   12227篇
  2012年   18260篇
  2011年   19158篇
  2010年   10920篇
  2009年   9951篇
  2008年   16856篇
  2007年   17661篇
  2006年   17523篇
  2005年   17453篇
  2004年   16346篇
  2003年   15255篇
  2002年   14243篇
  2001年   2307篇
  2000年   1795篇
  1999年   2512篇
  1998年   3293篇
  1997年   2760篇
  1996年   2368篇
  1995年   2257篇
  1994年   1907篇
  1993年   1691篇
  1992年   1419篇
  1991年   1258篇
  1990年   1112篇
  1989年   1051篇
  1988年   1061篇
  1987年   1037篇
  1986年   1000篇
  1985年   1038篇
  1984年   1290篇
  1983年   1188篇
  1982年   1420篇
  1981年   1352篇
  1980年   1162篇
  1979年   716篇
  1978年   767篇
  1977年   650篇
  1976年   597篇
  1975年   486篇
  1974年   491篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
To design synthetic microenvironments that elicit desired cell behaviors, we must better understand the molecular mechanisms by which cells interact with candidate biomaterials. Using cell lines with distinct alpha5beta1 integrin expression profiles, we demonstrate that this integrin mediates cell spreading on substrata coated with genetically engineered artificial extracellular matrix (aECM) proteins containing the RGD sequence (RGD-containing aECM protein [aRGD]) but lacking the PHSRN synergy site. Furthermore, aRGD-mediated adhesion stimulates an intracellular focal adhesion kinase (FAK) signal that is indicative of integrin tethering. Although both aRGD and the natural ECM protein fibronectin (FN) support alpha5beta1 integrin-mediated cell spreading, quantitative single-cell analysis revealed that aRGD-mediated spreading requires ten-fold greater threshold amount of integrin expression than FN-mediated spreading. Our analysis demonstrates that aRGD-based substrata mediate both biophysical (cell spreading) and biochemical (FAK signaling) events via the alpha5beta1 integrin, albeit with efficacy quantitatively distinct from that of natural ECM proteins that possess the full spectrum of adhesion and synergy domains.  相似文献   
82.
83.
84.
Dental management of patients with autoimmune vesiculobullous disorders is complicated because of prominent involvement of oral mucosa, increased risk of oral disease, and difficulty in rendering dental care. Although these diseases are relatively uncommon, dental practitioners should be familiar with the oral sequelae of these conditions and their management. Pemphigus vulgaris, cicatricial pemphigoid, and epidermolysis bullosa represent the most common autoimmune oral vesiculobullous diseases. This case-illustrated review summarizes the pathogenesis, diagnostic features, and natural history of oral vesiculobullous disorders, placing an emphasis on the treatment and prevention of associated oral disease aimed at maintaining a healthy, functional dentition.  相似文献   
85.
86.
87.
Originally described by Rosen in 1983, syringomatous nipple adenoma (SAN) is a tumor of disputed histogenesis, which can be problematic both diagnostically and therapeutically. 1 It is a benign primary tumor of breast epithelium with histology similar to that of the syringoma. In the current case, we describe a 40-year-old female with this lesion occurring within a supernumerary breast. This case represents, to our knowledge, the first such reported case, and represents a significant finding as its presence could lend some confusion as to whether or not this represents a benign primary process of breast or a potentially infiltrative tumor of the skin.  相似文献   
88.
89.
90.
Contrary to popular beliefs, a recent empirical study using eye tracking has shown that a non-clinical sample of socially anxious adults did not avoid the eyes during face scanning. Using eye-tracking measures, we sought to extend these findings by examining the relation between stable shyness and face scanning patterns in a non-clinical sample of 11-year-old children. We found that shyness was associated with longer dwell time to the eye region than the mouth, suggesting that some shy children were not avoiding the eyes. Shyness was also correlated with fewer first fixations to the nose, which is thought to reflect the typical global strategy of face processing. Present results replicate and extend recent work on social anxiety and face scanning in adults to shyness in children. These preliminary findings also provide support for the notion that some shy children may be hypersensitive to detecting social cues and intentions in others conveyed by the eyes. Theoretical and practical implications for understanding the social cognitive correlates and treatment of shyness are discussed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号